DTC P006B MAP – Exhaust Pressure Correlation

DTC P006B is a diagnostic trouble code indicating a correlation issue between the Manifold Absolute Pressure (MAP) sensor and the Exhaust Pressure sensor. Understanding and addressing this issue is crucial for maintaining your vehicle’s efficiency and performance. In this article, we’ll delve into the details of DTC P006B, exploring what it means, its potential causes, and how to diagnose and fix this issue effectively.

What is DTC P006B?

The P006B diagnostic trouble code (DTC) signifies that there is a discrepancy between the readings of the Manifold Absolute Pressure (MAP) sensor and the Exhaust Pressure sensor. The MAP sensor measures the pressure inside the intake manifold, while the Exhaust Pressure sensor measures the pressure in the exhaust system. These readings are essential for the engine control unit (ECU) to calculate the correct air-fuel mixture and ensure optimal combustion. When the ECU detects a correlation issue between these sensors, it means that their readings are not in sync, leading to potential engine performance issues.

Potential Causes of DTC P006B:

The P006B code is triggered when the ECM detects that the MAP sensor and Exhaust Pressure sensor readings are not aligned. This can happen due to several reasons:

  • Faulty MAP Sensor: The MAP sensor may be malfunctioning, providing incorrect pressure readings.
  • Faulty Exhaust Pressure Sensor: The Exhaust Pressure sensor may be malfunctioning, leading to incorrect pressure readings.
  • Wiring Issues: Damaged or corroded wiring or connectors associated with the MAP or Exhaust Pressure sensors can cause incorrect signals.
  • Vacuum Leaks: Leaks in the intake manifold can affect the MAP sensor’s readings.
  • Exhaust Leaks: Leaks in the exhaust system can affect the Exhaust Pressure sensor’s readings.
  • ECU Issues: Although rare, a malfunctioning ECU could incorrectly interpret the sensor signals.

Symptoms of P006B

When the P006B code is set, you might experience the following symptoms:

  • Check Engine Light (CEL) illuminated on the dashboard.
  • Reduced engine performance.
  • Poor fuel efficiency.
  • Rough idling or stalling.

Diagnostic and Repair Procedures for DTC P006B:

Diagnosing and resolving the P006B code requires a systematic approach:

  • Initial Inspection: Connect a diagnostic scanner to the vehicle’s OBD-II port to retrieve the trouble codes, including P006B. Record any additional codes and freeze frame data to understand the conditions under which the code was set.
  • Visual Inspection: Conduct a thorough visual inspection of the MAP and Exhaust Pressure sensors and their wiring harnesses. Look for signs of damage, corrosion, or disconnection.
  • Verify Sensor Readings: Use the diagnostic scanner to compare the readings of the MAP sensor and Exhaust Pressure sensor. Their readings should correlate accurately under various engine conditions.
  • Check Wiring and Connectors: Inspect the wiring and connectors for both sensors for any signs of damage, corrosion, or incorrect routing. Repair or replace any damaged wiring as necessary.
  • Test the MAP Sensor: Use a multimeter to test the MAP sensor’s voltage output and resistance. Compare the readings with the manufacturer’s specifications. Replace the MAP sensor if it is faulty.
  • Test the Exhaust Pressure Sensor: Similarly, test the Exhaust Pressure sensor to ensure it is functioning correctly. Replace the sensor if it is faulty.
  • Inspect for Vacuum Leaks: Check the intake manifold and associated vacuum lines for leaks. Repair any leaks found to ensure accurate MAP sensor readings.
  • Inspect for Exhaust Leaks: Check the exhaust system for leaks. Repair any leaks found to ensure accurate Exhaust Pressure sensor readings.
  • Check for ECU Issues: Although rare, inspect the ECU for any potential faults or software issues that could cause incorrect interpretation of sensor signals. Reprogram or replace the ECU if necessary.
  • Clear Codes and Perform Test Drive: After completing the repairs, clear the trouble codes from the vehicle’s memory using the diagnostic scanner. Perform a test drive to ensure the vehicle operates properly and that the P006B code does not return.


Understanding and addressing DTC P006B is essential for maintaining optimal engine performance and fuel efficiency. By following these detailed diagnostic and repair procedures, you can effectively address the P006B trouble code, ensuring the MAP and Exhaust Pressure sensors are correctly synchronized and interpreted by the ECU. Regular maintenance and careful inspection of sensors and wiring can help prevent this code from appearing. If you found this guide helpful, please share it with fellow automotive enthusiasts and technicians. For more detailed guides and tips on car maintenance and repair, visit our website.